The present invention relates to a propeller shaft applicable to an automotive vehicle and others.
Japanese Patent Application Publication No. 2013-194895 (JP 2013-194895 A), corresponding to U.S. Pat. No. 8,864,591 B2, discloses a propeller shaft for transmitting rotation from a drive source of a vehicle to driving wheels of the vehicle. The propeller shaft includes a shaft section extending in a vehicle longitudinal direction. The shaft section is connected at its first longitudinal end to a first shaft via a first constant velocity joint, and connected at its second longitudinal end to a second shaft via a second constant velocity joint, wherein the first shaft is connected to the drive source, and the second shaft is connected to the driving wheels.
Each constant velocity joint includes an outer ring member, an inner ring member, and a plurality of balls. The shaft section is provided with the outer ring member, wherein the outer ring member has a tubular shape. The inner ring member has a tubular shape, and is disposed radially inside the outer ring member. The balls are disposed between the outer ring member and the inner ring member for transmitting a torque therebetween. The inner ring member includes a female spline part, which is formed in an inner peripheral side of the inner ring member, and configured to engage with a male spline part formed in an outer peripheral side of the first or second shaft. The inner ring member includes a female-spline-side annular groove, which is formed and extending circumferentially in the inner peripheral side of the inner ring member, and is defined by a first side wall, a second side wall, and a bottom wall between the first side wall and the second side wall, wherein the second side wall is closer to the shaft section than the first side wall. The female-spline-side annular groove is configured to receive a circlip, wherein the circlip is disposed in a male-spline-side annular groove formed and extending circumferentially in the outer peripheral side of the first or second shaft, and configured to expand into the female-spline-side annular groove, to restrict movement of the first or second shaft in the axial direction of the shaft section with respect to the inner ring member. A circlip-restricting surface is formed in the first side wall of the female-spline-side annular groove. The circlip-restricting surface is formed as an inclined surface having a large angle with respect to the axial direction of the shaft section for ensuring a force restricting movement of the circlip in the axial direction of the shaft section.